@@ -76,16 +76,24 @@ type Repo interface {
type ClockedRepo interface {
Repo
+ // LoadClocks read the clocks values from the on-disk repo
LoadClocks() error
+ // WriteClocks write the clocks values into the repo
WriteClocks() error
+ // CreateTimeIncrement increment the creation clock and return the new value.
CreateTimeIncrement() (lamport.Time, error)
+ // EditTimeIncrement increment the edit clock and return the new value.
EditTimeIncrement() (lamport.Time, error)
+ // CreateWitness witness another create time and increment the corresponding
+ // clock if needed.
CreateWitness(time lamport.Time) error
+ // EditWitness witness another edition time and increment the corresponding
+ // clock if needed.
EditWitness(time lamport.Time) error
}
@@ -41,12 +41,15 @@ type Clock struct {
// Time is the value of a Clock.
type Time uint64
+// NewClock create a new clock with the value 1.
+// Value 0 is considered as invalid.
func NewClock() Clock {
return Clock{
counter: 1,
}
}
+// NewClockWithTime create a new clock with a value.
func NewClockWithTime(time uint64) Clock {
return Clock{
counter: time,
@@ -12,6 +12,7 @@ type Persisted struct {
filePath string
}
+// NewPersisted create a new persisted Lamport clock
func NewPersisted(filePath string) (*Persisted, error) {
clock := &Persisted{
Clock: NewClock(),
@@ -27,6 +28,7 @@ func NewPersisted(filePath string) (*Persisted, error) {
return clock, nil
}
+// LoadPersisted load a persisted Lamport clock from a file
func LoadPersisted(filePath string) (*Persisted, error) {
clock := &Persisted{
filePath: filePath,
@@ -40,11 +42,14 @@ func LoadPersisted(filePath string) (*Persisted, error) {
return clock, nil
}
+// Increment is used to return the value of the lamport clock and increment it afterwards
func (c *Persisted) Increment() (Time, error) {
time := c.Clock.Increment()
return time, c.Write()
}
+// Witness is called to update our local clock if necessary after
+// witnessing a clock value received from another process
func (c *Persisted) Witness(time Time) error {
// TODO: rework so that we write only when the clock was actually updated
c.Clock.Witness(time)